Negative use of the soil needs to be reversed

Although soil plays an important function for human well-beings, unsustainable food production practices that regard soils merely as an input-output system or medium, are degrading our precious soil resources.

Already, more than a quarter of our planet’s soils is facing degradation as a result of soil erosion, soil sealing, soil contamination and salinisation, loss of organic carbon and the depletion of vital nutrients. This negative view – and use – of soil needs to be reversed because according to the FAO, the planet will need to increase its food production by 60% by the year 2050 to feed the population. Soils on the African continent also face this problem and about 16% of its soils are compromised by degradation. It is estimated that effective and sustainable soil management implementation can increase food production by 58% over the long term by restoring degraded soils and building soil health in currently productive soils.

Sheila Storey, owner of Nemlab, a nematode diagnostic laboratory in South Africa, addressed Namibian producers at Noordoewer on how to spot the tell-tale signs of nematodes present in soil. Because they thrive in sandy soils, nematodes pose a significant threat to Namibian horticulture production. Storey demonstrated with various case studies how different crops are affected by different strains of nematodes. After researching nematodes for nearly 30 years, Storey has in-depth knowledge of nematode diagnostics, problems relating to nematodes and has until recently, taken on a holistic approach when making recommendations to producers.

In recent years, Storey’s interest has turned to preserving soil health when dealing with nematodes and she shared the principles of bio-fumigation with brassica crops as an alternative method of control. Brassica crops such as cabbage, broccoli, cauliflower and kale produce sulphur that when it decomposes and combines with other enzymes in soils, causes a fumigation effect in soil borne pathogens, such as nematodes.

As the importance of the agricultural sector has developed over the years, so too has the importance of formalising qualifications in the agricultural sector at vocational training level by developing skilled and successful commercial farmers. Dr Peter Lenhardt of the National Training Authority informed producers of what has already been achieved in t Namibia regarding vocational training, where practical and relevant skills for the Namibian horticulture sector will be imparted to willing trainees.

Francois Wahl of Agra spoke on the importance of taking soils samples and its packaging for sending to the laboratory for analysis, as well as how the results should be interpreted. He also gave a practical demonstration of how soil samples should be gathered and packaged for laboratory analysis.

Producers found the presentations enlightening and interacted with presenters. Producers took these learnings to heart to implement at their farms. Shetuuka Shetuuka, winner of the Horticulture Producer of the Year in the Emerging Scale category has started implementing the optimal supply of water to his crops of butternut and tomatoes. He has also started mulching with grass. “Although it is a lot of work, I started mulching which is very good because the grass protects the upper layer of the soil around my butternuts and tomatoes and the grass decomposes and adds value to the soil as well,” he said.

Building healthy soils in Namibia for food security will take the combined efforts of all producers and starts with promoting the sustainable management of soils to increase production and offer more nutritious crops. Innovative approaches will be required supporting the establishment and maintenance of healthy soils that supply essential nutrients, water, oxygen and root support that food producing plants need to grow and thrive – all with sustainable farming practices that limit harmful inputs that degrade soil health.